1. Field of the Invention
The present invention relates to a control device, a control method, and a control system applied to remote control of a plurality of devices connected in a network.
2. Description of the Related Art
A home network connecting a plurality of electronic devices present thereon has been developed for practical use. For example, the DLNA (Digital Living Network Alliance) has formulated specifications (guidelines) for mutual use of content such as moving image, music, and still image between digital AV (Audio Visual) devices and personal computers mutually connected by the home network. The content refers to a set of information in general which a person can view on a website or through a medium. Specifically, the content includes music, movies, text, comics, games, web pages, and so forth. According to the DLNA specifications, the following are specified as devices.
A DMS (Digital Media Server) is a content supply unit providing content. In the following description, the DMS. will be referred to as the server. Specifically, the DMS includes a hard disk, a video recorder, a personal computer, a video camera with an integrated recorder (so-called camcorder), a digital camera, and so forth.
A DMP (Digital Media Player) is a control reproduction unit having an interface function and a content reproduction function. In the following description, the DMP will be referred to as the player. Specifically, the DMP includes a television receiver, an audio system, a computer game machine, and so forth.
A DMR (Digital Media Renderer) is a reproduction unit having a function of reproducing digital content stored in the DMS. In the following description, the DMR will be referred to as the renderer. Specifically, the DMR includes a video monitor, a speaker, and so forth.
A DMC (Digital Media Controller) is a control unit having an interface function operated by a user. In the following description, the DMC will be simply referred to as the controller. Specifically, the DMC includes a remote controller, a mobile phone, a pocket personal computer, and so forth. The controller may be provided with not only the interface function but also a function of reproducing content.
In the home network constructed in accordance with the DLNA specifications, AV content stored in the server can be selected and reproduced by the player via the network, and AV content selected by the controller can be reproduced by the renderer. If the network is connected to a plurality of devices, a user selects one of the plurality of devices to be controlled by the controller. However, it is not easy to identify which device is the currently controlled target device (current target device). Therefore, there is a possibility of causing an operational error.
To address the above-described issue, Japanese Unexamined Patent Application Publication No. 2006-332772 proposed in the past proposes to display, on an operation panel of the controller, a thumbnail image showing the current target device.